Earphone system for mobile device and method for operating the same

ABSTRACT

An earphone system and method of operating an earphone system are provided. The earphone system includes a mobile device and an earphone. When a 4-pole earphone header of the earphone is inserted into an ear jack interface of the mobile device, the ear jack interface receives at least one input signal from earphone input elements of the earphone through the earphone header. The mobile device identifies the received at least one input signal through the ear jack interface and controls a particular user-function in response to the identified at least one input signal.

PRIORITY

This application claims the benefit under 35 U.S.C. §119(a) of a Koreanpatent application filed on Apr. 30, 2010 in the Korean IntellectualProperty Office and assigned Serial No. 10-2010-0041046, the entiredisclosure of which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a mobile device having an ear jackinterface. More particularly, the present invention relates to anearphone system and operation method thereof for identifying variousinput signals offered from an earphone connected to the ear jackinterface and thereby for controlling a particular user-function inresponse to the identified signal.

2. Description of the Related Art

Normally, a mobile device denotes a type of electronic device thatprovides mobility and portability. With remarkable growth of relatedtechnologies, a great variety of mobile devices, such as a mobilecommunication device and a Personal Digital Assistant (PDA), arebecoming increasingly popular these days. A typical mobile communicationdevice has a module for supporting a mobile communication function andthereby allows voice and data communications with other mobilecommunication devices through a base station. A typical PDA has aCentral Processing Unit (CPU), a memory unit, an Operating System (OS),and various programs and modules that operate based on the OS, andthereby allows various functions to collect, store, write and searchinformation.

Some functions of the mobile device, e.g., a call function, an audiofile play function, etc., inherently include a function to output audiosignals through a speaker provided on the mobile device. Alternatively,a user of the mobile device may use an earphone to prevent sounds frombeing heard outside or to hear clearer sounds.

For a connection with an earphone, a conventional mobile devicetypically includes a 4-pole ear jack interface. However, this 4-pole earjack interface only supports an audio signal output through right andleft earphone speakers and an audio signal input through an earphonemicrophone. Additionally, the 4-pole ear jack interface merelyrecognizes the insertion of an earphone and then only performs audioinput and output. Therefore, the utilization of such a conventional earjack interface is limited. Even if any external device can be connectedto the 4-pole ear jack interface, this may unfavorably cause great powerconsumption since a conventional mobile device should always monitor aconnection of an external device by continuously detecting the value ofan Analog Digital Converter (ADC) received through the ear jackinterface.

SUMMARY OF THE INVENTION

Aspects of the present invention are to address at least theabove-mentioned problems and/or disadvantages and to provide at leastthe advantages described below. According, an aspect of the presentinvention is to provide an earphone system, a mobile device forsupporting the earphone system, and an operation method for the earphonesystem, allowing various input elements to be connected to an ear jackinterface of the mobile device with reduced power consumption.

According to an aspect of the present invention, an earphone system isprovided. The system includes an earphone including a 4-pole earphoneheader and an earphone input unit, the earphone header having anearphone microphone terminal, and the earphone input unit beingconfigured to create at least one input signal for the control of auser-function of a mobile device and to send the at least one inputsignal to the mobile device through the earphone microphone terminal,and the mobile device including an ear jack interface including amicrophone electrode pin, the mobile device being configured to receivethe at least one input signal through the microphone electrode pin whenthe ear jack interface is connected to the earphone header, to identifythe received at least one input signal, and to control the user-functioncorresponding to the at least one identified input signal.

According to another aspect of the present invention, a mobile device isprovided. The device includes an ear jack interface for reception of a4-pole earphone header of an earphone, the ear jack interface includinga microphone electrode pin for connection to an earphone microphoneterminal of the earphone header, and a control unit configured toreceive at least one input signal through the microphone electrode pin,the input signal being created by earphone input elements of theearphone, to identify the received input signal, and to control aparticular user-function corresponding to the identified input signal.

According to still another aspect of the present invention, a method foroperating an earphone system is provided. The method includesdetermining whether a 4-pole earphone header of an earphone is insertedinto an ear jack interface, receiving at least one input signal fromearphone input elements of the earphone through the earphone header,identifying the received at least one input signal through the ear jackinterface, and controlling a particular user-function in response to theidentified at least one input signal.

Other aspects, advantages and salient features of the invention willbecome apparent to those skilled in the art from the following detaileddescription, which, taken in conjunction with the annexed drawings,discloses exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certainexemplary embodiments of the present invention will be more apparentfrom the following description taken in conjunction with theaccompanying drawings, in which:

FIG. 1 is a perspective view illustrating an earphone system inaccordance with an exemplary embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a mobiledevice in accordance with an exemplary embodiment of the presentinvention.

FIG. 3 is a schematic view illustrating an ear jack interface and anearphone in the earphone system in accordance with an exemplaryembodiment of the present invention.

FIG. 4 is a schematic view illustrating signal identification in an earjack interface in accordance with an exemplary embodiment of the presentinvention.

FIGS. 5 and 6 are flow diagrams illustrating a method for operating anear phone system in accordance with an exemplary embodiment of thepresent invention.

Throughout the drawings, it should be noted that like reference numbersare used to depict the same or similar elements, features, andstructures.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The following description with reference to the accompanying drawings isprovided to assist in a comprehensive understanding of exemplaryembodiments of the invention as defined by the claims and theirequivalents. It includes various specific details to assist in thatunderstanding but these are to be regarded as merely exemplary.Accordingly, those of ordinary skill in the art will recognize thatvarious changes and modifications of the embodiments described hereincan be made without departing from the scope and spirit of theinvention. In addition, descriptions of well-known functions andconstructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are notlimited to the bibliographical meanings, but, are merely used by theinventor to enable a clear and consistent understanding of theinvention. Accordingly, it should be apparent to those skilled in theart that the following description of exemplary embodiments of thepresent invention is provided for illustration purpose only and not forthe purpose of limiting the invention as defined by the appended claimsand their equivalents.

It is to be understood that the singular forms “a,” “an,” and “the”include plural referents unless the context clearly dictates otherwise.Thus, for example, reference to “a component surface” includes referenceto one or more of such surfaces.

FIG. 1 is a perspective view illustrating an earphone system inaccordance with an exemplary embodiment of the present invention.

Referring to FIG. 1, the earphone system is composed of a mobile device100 and an earphone 200. Although the following disclosure is based onthe earphone 200 connected to an ear jack interface of the mobile device100, this is exemplary only and not to be considered as a limitation ofthe present invention. Instead of the earphone 200, any otherequivalents, such as an external speaker, can be connected to the earjack interface.

The mobile device 100 includes a display unit 140 and an ear jackinterface 170 and may transmit or receive audio signals, generatedduring a content playback or a voice call, to or from the earphone 200through the ear jack interface 170. While connected to the earphone 200,the mobile device 100 may identify signals created by and received fromvarious input elements, such as volume up/down keys and call/stop keys,provided in the earphone 200. Also, the mobile device 100 may control aparticular user-function in response to the identified signal. Themobile device 100 may recognize the connection of the earphone 200 froman interrupt created when a header of the earphone 200 is inserted intothe ear jack interface 170, and may support particular functions relatedto the earphone 200. Each individual element of the mobile device 100will be described in more detail with reference to FIG. 2 below.

The earphone 200 is a device that is connected to the ear jack interface170 of the mobile device 100. The earphone 200 receives audio signalsfrom the mobile device 100 and converts the received audio signals intosounds. The earphone 200 of a 4-pole type may have an earphone header210 that is inserted into the ear jack interface 170, an earphone inputunit 220 that has an earphone microphone (EAR-MIC), volume up/down keys221, call/stop keys 223, and the like, and an earphone speaker 230 thatmay have left and right earphone speakers 231 and 233. The earphone 200acquires sounds and converts them into audio signals through theearphone microphone (EAR-MIC) and delivers the audio signals to themobile device 100 through the earphone header 210. In the earphone 200,each element of the earphone input unit 220 may be activated and form aspecific path according to a user's manipulation. Namely, each activatedelement of the earphone 200 may establish a path having a specificresistance value. Also, depending on a voltage value that is variedaccording to differences in resistance values in each path, the mobiledevice 100 may determine which element is activated in the earphone 200.Related descriptions will be given later with reference to FIG. 3.

As discussed hereinbefore, the earphone system supports functions of theearphone 200 based on an interrupt created when the earphone 200 isconnected to the ear jack interface 170. Furthermore, the earphonesystem identifies various signals created by and received from variousinput elements, such as volume up/down keys and call/stop keys, providedin the earphone 200, and controls a particular user-function in responseto the identified signal. Therefore, a user can easily adjust an audiovolume, make a call, stop a call, etc., by manipulating the 4-poleearphone 200 without directly handing the mobile device 100.

FIG. 2 is a block diagram illustrating a configuration of a mobiledevice in accordance with an exemplary embodiment of the presentinvention.

Referring to FIG. 2, the mobile device 100 of this invention may includea Radio Frequency (RF) unit 110, an input unit 120, an audio processingunit 130, a display unit 140, a memory unit 150, an ear jack interface170, and a control unit 160.

The mobile device 100 having the above-specified elements is structuredto create an interrupt when the earphone 200 is connected to the earjack interface 170. When such an interrupt occurs, the mobile device 100can shift an audio path to the earphone 200. Also, if any interrupt iscaused by a voltage drop under a given value in the ear jack interface170, the mobile device 100 can detect the magnitude of a voltage dropand thereby identify the type of an input signal created by and receivedfrom the earphone 200. The mobile device 100 can perform a particularuser-function in response to the identified input signal of the earphone200. Each individual element of the mobile device 100 will be describedbelow in more detail.

The RF unit 110 is a kind of communication module for supporting amobile communication service of the mobile device 100. The RF unit 110may employ a Global System for Mobile communication (GSM) module, a CodeDivision Multiple Access (CDMA) module, or the like according to thetype of mobile communication service and, based on such a module,establishes a communication channel with a mobile communication system.For this, the RF unit 110 may include an RF transmitter that up-convertsthe frequency of an outgoing signal and amplifies the signal, an RFreceiver that amplifies with low-noise an incoming signal anddown-converts the frequency of the signal, and the like. The RF unit 110may be essential or not according to the type of mobile device 100.Namely, if the mobile device 100 supports a mobile communicationfunction based on a base station, the RF unit 110 is essential. However,in case of a monitor, a music player, etc. that requires no mobilecommunication function, the RF unit 110 may be omitted according to thedesigner's or manufacturer's intention.

More particularly, the RF unit 110 of this invention establishes a callchannel with any other device in response to a user's manipulation andsends or receives audio signals to or from the other device. At thistime, audio signals received by the RF unit 110 may be delivered to theearphone speaker 230 of the earphone 200 through the ear jack interface170.

The input unit 120 includes a plurality of input keys and function keysto receive a user's input action and to set various functions. Thefunction keys may have navigation keys, side keys, shortcut keys, andany other special keys defined to perform particular functions.Additionally, the input unit 120 receives a user's key manipulation forcontrolling the mobile device 100, creates a corresponding input signal,and delivers it to the control unit 160.

More particularly, the input unit 120 may create various input signalsfor controlling user-functions of the mobile device 100 and send them tothe control unit 160. For instance, depending on a user's manipulation,the input unit 120 may create an input signal for entering or selectinga desired phone number, an input signal for trying to connect a callbased on the desired phone number, an input signal for selecting andplaying a desired file stored in the memory unit 150, or the like, anddeliver it to the control unit 160.

The audio processing unit 130 may include a speaker (SPK) for outputtingaudio signals delivered from the control unit 160, and a microphone(MIC) for collecting audio signals while a particular application isrunning. When the RF unit 110 is activated, the audio processing unit130 may output audio signals received through the RF unit 110 or audiosignals of selected content to the speaker (SPK). More particularly,before the earphone 200 is connected to the ear jack interface 170, theaudio processing unit 130 forms audio output and input paths based onthe speaker (SPK) and the microphone (MIC). However, if the earphone 200is connected to the ear jack interface 170, the audio processing unit130 removes the above paths based on the speaker (SPK) and themicrophone (MIC) and forms new audio output and input paths based on theearphone-microphone (EAR-MIC) and the earphone speaker 230 in theearphone 200. Therefore, audio signals of the mobile device 100 may beoutput through the ear jack interface 170 of the mobile device 100 andthe earphone speaker 230 of the earphone 200, and audio signalscollected by the earphone microphone (EAR-MIC) may be input to thecontrol unit 160 through the ear jack interface 170 and the audioprocessing unit 130.

The display unit 140 represents information, including various menus ofthe mobile device 100, input by a user or offered to a user. Namely, thedisplay unit 140 may visually offer a variety of screen views inconnection with the use of the mobile device 100, such as an idlescreen, a menu screen, a message writing screen, a call screen, and thelike.

More particularly, the display unit 140 may enter into various statesaccording to the connection of the ear jack interface 170. That is, whenthe earphone 200 is connected to the ear jack interface 170 during acall, the display unit 140 may be automatically turned off to minimizepower consumption. If any input signal for instructing a supply of poweris input, the display unit 140 may be turned on to again display thescreen that was displayed just before being turned off. Additionally,when the earphone 200 is connected to the ear jack interface 170, thedisplay unit 140 may output a given message or any other equivalents toannounce the connection to a user. This function may be disabled at auser's request. Furthermore, if any input signal is delivered from theearphone 200, the display unit 140 may output a related screen. Forinstance, when receiving an input signal from the volume up/down keys orcall/stop keys of the earphone 200, the display unit 140 may display agiven image related to a selected input key to offer a feedback to auser. This function may also be disabled at a user's request.

Meanwhile, the display unit 140 may be formed of a Liquid CrystalDisplay (LCD), Organic Light Emitting Diodes (OLEDs), or any otherequivalent. In case of being fabricated in the form of a touch screen,the display unit 140 may act as an input unit as well. In this case, thetouch screen may be composed of a display panel and touch sensorsdisposed thereon. Also, the mobile device 100 in this case may offervarious menu screens available and suitable for the touch screen.

The memory unit 150 stores a variety of applications required forfunctions related to an exemplary embodiment of this invention orrequired for execution or playback of various types of files. If themobile device 100 employs a touch screen, the memory unit 150 may storea key map, a menu map, etc. required for the operation of the touchscreen. Here, the key map may have various well known types such as akeyboard map, a 3*4 key map, a QWERTY key map, or a special control keymap suitable for the operation of a currently activated application.Also, the menu map may be a special menu map suitable for the operationof a currently activated application or a normal menu map having menuitems offered by the mobile device. The memory unit 150 may consist of aprogram region and a data region.

The program region may store an Operating System (OS) for booting andoperating the mobile device 100, and applications required forperforming various functions or required for executing or playingvarious files, such as a call application, a web browser for surfing onthe Internet, a Moving Picture Experts Group (MPEG) MPEG-1 or MPEG-2Audio Layer III (MP3) application for playing digital sounds, an imageviewer application for showing image files, a video player application,and the like. More particularly, the program region may store anearphone support application for supporting the function of the earphone200.

The earphone support application is a specialized program that isactivated when the earphone 200 is connected to the ear jack interface170, controls the shift of an audio path toward the earphone 200,identifies an input signal received from the earphone 200, and controlsa particular user-function based on the identified input signal. For theabove, the earphone support application may be loaded in the controlunit 160 and may contain a routine for determining whether the earphone200 is connected to the ear jack interface 170, a routine forcontrolling the shift of audio output and input paths, a routine foridentifying an input signal received from the earphone 200, and aroutine for controlling a particular user-function in response to theidentified input signal. The user-function control routine may have asubroutine for controlling specific options of a currently activateduser-function and a subroutine for activating a selected user-functionor inactivating the activated user-function.

The data region stores data created or received while the mobile device100 is used, and also may store various contents depending upon the typeof the mobile device. In addition, if the display unit 140 is formed ofa touch screen, the data region may store user's inputs received fromthe touch screen. More particularly, the data region may store an inputsignal table used for controlling user-functions based on the connectionof the earphone 200. The input signal table may define a mappingrelation between types of input signals received from the earphone 200and commands for executing user-functions. For instance, the inputsignal table may contain information about a command to increase avolume of a currently activated user-function in response to an inputsignal of the volume up key of the earphone 200. Such an input signalsubstantially corresponds to a specific voltage value, so the inputsignal table may be used for the creation of commands according tovarious voltage values.

The ear jack interface 170 is provided on a side of the mobile device100 in a form that allows the earphone header 210 to be inserted andthen fixed. The ear jack interface 170 may have several pins such thatvarious types of earphones can be used. A related description will begiven later with reference to FIG. 3.

The control unit 160 controls a power supplying and initializing processfor each element of the mobile device 100. After initializing, thecontrol unit 160 may perform a control for a particular user-functionselected in response to the connection of the earphone 200. Morespecifically, the control unit 160 may employ the above-discussedearphone support application and determine whether the earphone 200 isconnected to the ear jack interface 170. For this, the mobile device 100may equip the ear jack interface 170 with terminals or electrode pinsfor keeping a reference voltage. The mobile device 100 may recognize theconnection of the earphone 200 by detecting a drop of the referencevoltage caused by the connection of the earphone 200. Additionally, thecontrol unit 160 may establish and control a signal path of the earphone200 that is in contact with various electrode pins of the ear jackinterface 170. A related description will be given hereinafter withreference to FIG. 3.

FIG. 3 is a schematic view illustrating an ear jack interface and anearphone in an earphone system in accordance with an exemplaryembodiment of the present invention.

Referring to FIG. 3, the ear jack interface 170 may have five electrodepins denoted respectively by reference numbers 1, 2, 3, 4 and 5.Specifically, the first electrode pin 1 is a microphone electrode pin tobe connected to an earphone microphone terminal M of the earphone header210. The second electrode pin 2 is a ground electrode pin to beconnected to a ground terminal G of the earphone header 210. The thirdelectrode pin 3 is a right speaker electrode pin to be connected to aright earphone speaker terminal R of the earphone header 210. The fourthelectrode pin 4 is a left speaker electrode pin to be connected to aleft earphone speaker terminal L of the earphone header 210. The fifthelectrode pin 5 is an optional electrode pin to be connected to theground terminal G of the earphone header 210. More particularly, thefifth electrode pin 5 may be used to generate an interrupt caused by theconnection of the earphone 200. Namely, when the fifth electrode pin 5is grounded through the connection of the earphone 200 under conditionswhere a given reference voltage is applied to the fifth electrode pin 5,the control unit 160 may determine that the earphone 200 is connected byrecognizing a change of the reference voltage as an interrupt.

The third and fourth electrode pins 3 and 4 may be connected to the sameterminal of the earphone header 210 in some types of earphones 200. Morespecifically, if the earphone 200 is a stereo type, the third and fourthelectrode pins 3 and 4 are connected respectively to the right and leftearphone speaker terminals R and L which are separately formed. However,if the earphone 200 is a monaural type, the third and fourth electrodepins 3 and 4 may be connected to a single speaker terminal which isformed without distinguishing right and left speakers from each other.Nevertheless, since this invention is to identify input signals receivedthrough the earphone microphone terminal M, this invention may beapplied to any type of earphone 200, namely, regardless of mono orstereo. In this disclosure, a stereo type of earphone 200 is exemplarilyused.

The earphone header 210 may have four terminals interconnected to therespective elements of the earphone 200. Specifically, the earphoneheader 210 may have the earphone microphone terminal M, the groundterminal G, the right earphone speaker terminal R, and the left earphonespeaker terminal L. The right earphone speaker terminal R isinterconnected to the right earphone speaker 231, and the left earphonespeaker terminal L is interconnected to the left earphone speaker 233.The earphone-microphone terminal M is interconnected to each of theearphone-microphone (EAR-MIC), the volume up/down keys 221, and thecall/stop keys 223 contained in the earphone input unit 220. The volumeup/down keys 221 include a volume up key and a volume down key, and thecall/stop keys 223 include a call key and a call stop key. In FIG. 3,each key is represented to be a resistance. Namely, the first resistanceR1 indicates the volume up key, and the second resistance R2 indicatesthe volume down key. Similarly, the third resistance R3 indicates thecall key, and the fourth resistance R4 indicates the call stop key. Moreparticularly, the resistance of each key may be different in value fromthe others. As discussed above, when the earphone header 210 is insertedinto the ear jack interface 170, it comes in contact with the respectiveelectrode pins of the ear jack interface 170.

FIG. 4 is a schematic view illustrating signal identification in an earjack interface in accordance with an exemplary embodiment of the presentinvention.

Referring to FIG. 4, the ear jack interface 170 may have an AnalogDigital Converter (ADC) 171 and a comparator 173. The ADC 171 isconnected between the first electrode pin 1 of the ear jack interface170 and the comparator 173. The comparator 173 compares a voltagedelivered through the first electrode pin 1 with the reference voltagesuch that a selected user-function may be controlled according tocomparison results. For instance, if only the earphone-microphone(EAR-MIC) is connected to the first electrode pin 1, an input value ofthe comparator 173 becomes about 1.3V. In this case, an audio signalinput through the earphone-microphone (EAR-MIC) may be offered to thecontrol unit 160 along a signal path.

Meanwhile, when any selected key of the earphone input unit 220 isactivated, a voltage applied to the first electrode pin 1 through theearphone-microphone terminal M may be dropped under 1.3V due to theresistance of the selected key. Here, the magnitude of a voltage dropmay be adjusted through variations in resistance. Also, as discussedabove, the respective keys of the earphone input unit 220 may havedifferent resistance values. Such resistance values may be adjusted tocause a voltage drop under the reference voltage (e.g., 0.75V) of thecomparator 173. When any selected key is activated, a voltage dropoccurs and the comparator 173 may offer comparison results depending onsuch a voltage drop to the control unit 160. Therefore, even though thecontrol unit 160 does not continuously monitor the comparator 173, thecontrol unit 160 can recognize a selected key by detecting the magnitudeof a voltage drop output from the comparator 173. The reference voltageof the comparator 173 may be varied according to a designer's intention.Also, the resistance values of the respective keys may be variedaccording to a designer's intention.

As discussed hereinbefore, the earphone system according to an exemplaryembodiment of the present invention and the mobile device using theearphone system may identify various signals of the earphone input unit220 in the earphone 200 when the 4-pole earphone 200 is connected, andmay control a particular user-function in response to the identifiedsignal. Although the earphone input unit 220 is described as having thevolume up/down keys and the call/stop keys, this is exemplary only andnot to be considered as a limitation of the present invention.Alternatively or additionally, the earphone input unit 220 may have anyother various keys such as power turn-off key, a search key, etc.

Now, an exemplary method for operating an earphone system will bedescribed in more detail with reference to FIGS. 5 and 6.

FIGS. 5 and 6 are flow diagrams illustrating a method for operating anear phone system in accordance with an exemplary embodiment of thepresent invention. The following discussion will be focused on a processflow in the mobile device 100.

Referring to FIGS. 5 and 6, when power is supplied to the mobile device100, the control unit 160 performs a booting process and initializes therespective elements of the mobile device 100. Then, based on predefinedschedule information, the control unit 160 outputs an idle screen on thedisplay unit 140 in step 501. If the schedule information containsinstructions to activate a particular user-function, the control unit160 may activate the user-function in this step according to theschedule information.

In step 503, the control unit 160 may determine whether the earphone 200is connected to the ear jack interface 170 of the mobile device 100,namely whether the earphone header 210 is inserted into the ear jackinterface 170. If it is determined in step 503 that there is noconnection of the earphone 200, the control unit 160 may activate aselected user-function according to an input signal of the input unit120 and then, based on the audio processing unit 130, control aprocessing of audio signals in step 505.

On the other hand, if it is determined in step 503 that the earphone 200is connected to the ear jack interface 170, the control unit 160 mayshift current audio output and input paths to new paths based on theearphone 200 in step 507. Thereafter, the control unit 160 may determinewhether an input signal for making a call is received from the earphone200 in step 509. If so, the control unit 160 may try to make a call withthe last phone number in a call history and also support a relateduser-function in step 511. In step 512, the control unit 160 maydetermine whether an input signal for stopping a call is received fromthe earphone 200. If so, the control unit 160 may return to step 509.

If it is determined in step 509 that there is no input signal for makinga call, the control unit 160 may activate a selected user-function inresponse to any other input signal in step 513.

In step 515, the control unit 160 may determine whether an input signalcorresponding to the volume up/down keys is received from the earphone200. If so, the control unit 160 may increase or decrease a sound volumeof a currently activated user-function in step 517. Then the controlunit 160 may return to step 513.

On the other hand, if it is determined that there is no input signal instep 515, the control unit 160 may further determine whether theearphone 200 is disconnected from the ear jack interface 170, namelywhether the earphone header 210 is withdrawn from the ear jack interface170 in step 519. If it is determined in step 519 that there is nodisconnection of the earphone 200, the control unit 160 may return tostep 513.

If it is determined in step 519 that there is a disconnection of theearphone 200, the control unit 160 may shift again the audio output andinput paths based on the earphone 200 to the original paths based on theaudio processing unit 130 while keeping a currently activateduser-function in step 521. In step 523, the control unit 160 maydetermine whether an input signal for inactivating the currentuser-function is received. If it is determined in step 523 that there isno inactivating signal, the control unit 160 may return to step 521.Alternatively, if it is determined in step 523 that there is aninactivating signal for the user-function, the control unit 160 mayfurther determine whether an input signal for turning off the mobiledevice is received in step 525. If there is no turn-off signal, thecontrol unit 160 may return to the initial step 501.

The control unit 160 may automatically lock the input unit 120 when theearphone 200 is connected. Additionally, when a call request signal isreceived from the external entity, the control unit 160 may deliver arelated signal to the earphone 200. Also, when a call acceptance signalis received from the earphone 200, the control unit 160 may perform afunction to make a call and then form audio paths based on the earphone200.

As discussed above, an interrupt occurs whenever the mobile device 100receives any input signal from the earphone 200. Since the control unit160 can recognize the creation of a specific input signal from theoccurrence of an interrupt, the mobile device 100 does not require acontinuous monitoring for determining the creation of input signals bythe earphone 200. Therefore, unnecessary power consumption is reduced.

According to the above-discussed method for operating the earphonesystem, when the earphone 200 is connected to the ear jack interface170, the mobile device 100 can activate or inactivate a particularuser-function or control options of the activated user-function inresponse to an input signal of the earphone 200.

The above-discussed mobile device 100 may essentially or selectivelyinclude any other elements. For instance, the mobile device 100 mayfurther include a short range communication module, a digital cameramodule, a wired or wireless data transmission interface, an Internetaccess module, a digital broadcast receiving module, and so forth.According to a digital convergence tendency, such elements may bevaried, modified and improved in various ways, and any other elementsequivalent to the above elements may be additionally or alternativelyequipped in the mobile device 100. Meanwhile, as will be understood bythose skilled in the art, some of the above-mentioned elements in themobile device 100 may be omitted or replaced with another.

Additionally, the mobile device 100 of this invention may include anytype of electronic devices that has the ear jack interface 170. Forinstance, the mobile device 100 may include communication devices,multimedia players and their application equipment, especially includingmany mobile communication terminals based on various communicationprotocols, a Portable Multimedia Player (PMP), a digital broadcastingplayer, a Personal Digital Assistant (PDA), a music player (e.g., an MP3player), a portable game console, a smart phone, a notebook, a handheldpersonal computer, etc.

While this invention has been shown and described with reference tocertain exemplary embodiments thereof, it will be understood by thoseskilled in the art that various changes in form and details may be madetherein without departing from the spirit and scope of the invention asdefined by the appended claims and their equivalents.

1. An earphone system comprising: an earphone including a 4-poleearphone header and an earphone input unit, the earphone header havingan earphone microphone terminal, and the earphone input unit beingconfigured to create at least one input signal for the control of auser-function of a mobile device and to send the at least one inputsignal to the mobile device through the earphone microphone terminal;and the mobile device including an ear jack interface including amicrophone electrode pin, the mobile device being configured to receivethe at least one input signal through the microphone electrode pin whenthe ear jack interface is connected to the earphone header, to identifythe received at least one input signal, and to control the user-functioncorresponding to the identified at least one input signal.
 2. Theearphone system of claim 1, wherein the earphone input unit comprises atleast one of: volume up/down keys for increasing or decreasing a volumeof an audio signal delivered from the mobile device to the earphone;call/stop keys for making or stopping a call of the mobile device; andan earphone microphone for collecting sounds.
 3. The earphone system ofclaim 1, wherein the ear jack interface further comprises: a groundelectrode pin connected to a ground terminal of the earphone header; anda speaker electrode pin connected to right and left earphone speakerterminals of the earphone header.
 4. The earphone system of claim 3,wherein the ear jack interface further comprises: an electrode pin towhich a reference voltage is applied so as to detect the insertion ofthe earphone header.
 5. The earphone system of claim 1, wherein the earjack interface further comprises: a ground electrode pin connected to aground terminal of the earphone header; a right speaker electrode pinconnected to a right earphone speaker terminal of the earphone header;and a left speaker electrode pin connected to a left earphone speakerterminal of the earphone header.
 6. The earphone system of claim 1,wherein the earphone input unit creates the at least one input signal bychanging a resistance of a signal path to which the earphone microphoneterminal is connected.
 7. A mobile device comprising: an ear jackinterface for reception of a 4-pole earphone header of an earphone, theear jack interface including a microphone electrode pin for connectionto an earphone microphone terminal of the earphone header; and a controlunit configured to receive at least one input signal through themicrophone electrode pin, the input signal being created by earphoneinput elements of the earphone, to identify the received input signal,and to control a particular user-function corresponding to theidentified input signal.
 8. The mobile device of claim 7, wherein theear jack interface further includes: an Analog Digital Converter (ADC)connected to the microphone electrode pin; and a comparator fordetecting a voltage drop of the ADC under a given value.
 9. The mobiledevice of claim 8, wherein the control unit is further configured toidentify types of the input signals created by the earphone inputelements according to a voltage value output from the comparator. 10.The mobile device of claim 7, further comprising: a memory unit forstoring an input signal table that defines a mapping relation betweentypes of the input signals created by the earphone input elements andcommands for executing user-functions.
 11. The mobile device of claim 7,wherein the control unit is further configured to identify the inputsignal received from the earphone as being received from at least one ofvolume up/down keys and call/stop keys and, based on the identifiedsignal, to perform one of a volume up/down function and a call/stopfunction.
 12. A method for operating an earphone system, the methodcomprising: determining whether a 4-pole earphone header of an earphoneis inserted into an ear jack interface; receiving at least one inputsignal from earphone input elements of the earphone through the earphoneheader; identifying the received at least one input signal through theear jack interface; and controlling a particular user-function inresponse to the identified at least one input signal.
 13. The method ofclaim 12, wherein the identifying of the at least one input signalincludes: comparing a given reference voltage with a voltage drop outputfrom a microphone electrode pin provided in the ear jack interface; andidentifying the input signal according to comparison results.
 14. Themethod of claim 12, wherein the controlling of the user-functionincludes: receiving the identified at least one input signal; andretrieving information about the particular user-function correspondingto the identified at least one input signal from an input signal tablethat defines a mapping relation between types of the input signals andcommands for executing the user-functions.
 15. The method of claim 12,wherein the identified at least one input signal comprises one of avolume up signal, a volume down signal, a call signal, and a call stopsignal.
 16. The method of claim 12, wherein the particular user-functionis one of a function to increase or decrease a sound volume and afunction to make or stop a call.